Age, education and occupation as determinants of trends in body mass index in Finland from 1982 to 1997.

Objective: To investigate trends in body mass index (BMI) and prevalence of obesity among adults in Finland from 1982 to 1997, and to identify population groups with increasing obesity.
Subjects: Random samples from the national population register including men and women aged 25-64 y (n = 24604, total).
Design: Four cross-sectional surveys carried out in three areas in Finland every fifth year since 1982.
Measurements: Weight and height were measured, and data on occupation and education level were collected by a self-administered questionnaire.
Results: The mean BMI increased in both genders. In men, the upward trend was greatest (the increase of 1.3 kg/m2 in 15 y) in the oldest age group (55-64 y), and was found also (the increase of 0.6 kg/m2) in the youngest age group (25-34 y), whereas in women, the upward trend was most prominent (the increase of 0.9 kg/m2) in the youngest age group. BMI increased in all educational groups in men, but in women the upward trend seemed to be greatest in the lowest educational group. The upward trends were most prominent among retired and unemployed men, while in women changes in BMI were similar in all occupational groups.
Conclusion: The strongest upward trend in BMI was found in the oldest men, in the youngest age group in both genders and, in particular, among men who were outside the labor force. Education is still a strong determinant of obesity, especially in women, although the social gradient in BMI has not widened in the 1990s.